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Hello everyone,
New to the site just looking for a little help with ferrography and some statistical analysis. I am looking to set up some thresholds for an alarm system that will monitor a piece of equipment.

I am curious to wether anyone has ever used an ferrography techniques such as wear particle concentration(WPC), or Percent Large Particle (PLP)and if you may have any valuable information about it to help me out.

Also, I am trying to determine wether the information I have is normally distributed or not to know what kind of thresholds to apply to certain peices of equipment. Just wondering if anyone knows any simple techniques to find normality?

Thanks in advanced,

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Hi Scott, we work on the microscope at all times and completing WDA we can easily particle count but with Ferrography it's a little difficult to accurately particle count so I would be inclined to particle count by Laser and I would be setting an ISO 16/13 for low pressure hydraulics as normal wear and an ISO 17/14 for gear drives as normal wear and once the application exceeds these limits becoming more contaminated then by using Wear Debris Analysis or Ferrography the contaminate can be identified and removed if necessary, ie: gelled lubricant will lift the particle count but does not usually affect reliability, Noria has limits set in their documentation plus our website has a doc called "It's all about Size" also has limits towards the end of the doc, the big advantage with monitoring by microscope is we can root cause the application on every oil sample and advise corrections and the customer can next see the contaminates disappear as they service and as you have already decided a new application run in on the microscope you will be able to see the break in wear debris then with a couple of oil changes the application settle down to a low rate of wear if the setup is OK and if not it will be immediately apparent what is causing the difficulty,
Rob S
PS There is a download section on please feel free to do so if the the data is of use

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